000 AXPZ20 KNHC 230356 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sat Jun 23 2018 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to a 1010 mb low pressure near 12N104W to a 1010 mb low pressure near 12N116W to 09N121W. The ITCZ continues from 09N121W to 08N130W to 09N139W. Scattered moderate convection is noted from 10N to 15N between 100W and 120W, and from 05N to 13N to the west of 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate NW winds are forecast to continue across the waters west of Baja California through Sat morning before beginning to gradually diminish through the weekend, as a broad surface trough shifts westward to the NE Pacific waters. Winds west of the peninsula will become variable less than 15 kt through the weekend. However, southerly winds will increase inside the Gulf of California this weekend, becoming fresh to strong southeasterly N of 28N Sat morning, continuing into Sun morning. Seas in the northern Gulf of California will build to 6-9 ft by Sat afternoon, then subside Sun along with a decrease in surface winds. Further south, long period cross-equatorial SW swell reaches the waters off Southern Mexico with seas to 6 ft, forecast to increase to 7 ft by Sat afternoon. Seas are expected to subside Mon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The monsoon trough will meander between 09N and 13N the next several days. Light to gentle winds will prevail north of the monsoon trough, with gentle to moderate S to SW winds expected south of the trough axis. Long period cross-equatorial SW swell is across southern forecast waters with seas to 8 ft. The swell will propagate further north to the offshore waters of Costa Rica and Colombia today, Sat and then will gradually subside through Sun. REMAINDER OF THE AREA... High pressure north of the area centered near 36N138W extends a ridge SE to near the Revillagigedo Islands. Moderate to fresh tradewinds prevail from 11N to 22N west of 135W with seas generally ranging between 6 to 7 ft. Light to gentle winds dominate the remainder of the basin. Fresh to strong tradewinds from 07N to 09.5N between 138 and 140W will gradually diminish through early Sat as a trough west of the area continue to move west. Seas are currently 8 ft in mixed swell and will gradually subside to 6-7 ft through Sat. Northerly swell will propagate into the northern waters with seas building to 8 ft north of 29N between 123W and 127W early Sun. Cross-equatorial southerly swell with seas to 9 ft are south of 10N and west of 90W and will continue through Sunday evening. Low pressure centered near 12N116W and embedded along the monsoon trough has an estimated pressure of 1010 mb. Model guidance shows this low emerging from the trough and drifting northward with a gradual increase in intensity through the weekend. Active thunderstorms will continue in the vicinity of this low through the weekend and early next week. A 1010 mb low pressure is near 12N104W generating scattered moderate convection from 10N to 15N between 100W and 115W. Global models guidance indicate there is a high chance for this low to develop into a tropical cyclone SW of Mexico early next week. $$ Ramos